Method of stiffening fabric shoe uppers



April 1968 w. L. HOCHNER 3,380,869

METHOD OF STIFFENING FABRIC SHOE UPPERS Filed Sept. 21, 1964 INVENT OR 7i wZierL Hoc]uw 7" I ATTORNEYS United States Patent "ice 3,380,869 METHOD OF STIFFENING FABRIC SHOE UfPERS Walter L. Hochner, Wilmington, Del., assignor to Kaumagraph Company, a corporation of Delaware Continuation-impart of application Ser. No. 311,510,

Sept. 25, 1963. This application Sept. 21, 1964, Ser.

4 Claims. (Cl. 156230) ABSTRACT OF THE DISCLOSURE Fabric uppers for shoes are stiffened by applying thermoplastic stiffening substance to the toe portion of each shoe upper and simultaneously applying heat and presure to the toe portion and the thermoplastic stiffening substance to impregnate the thermoplastic stiffening substance into the toe portion.

This application is a continuation-in-part of application Ser. No. 311,510, filed Sept. 25, 1963, now abandoned.

This invention relates to a method and transfer for stiffening a fabric portion of a shoe, and more particularly to a method and transfer for stiffening the toe portion of a shoe upper.

In making canvas shoes, it is common to apply a heat activated cloth to the toe area of the fabric upper to stiffen it and maintain it arched and spaced above the toes. This involves expenditure of material and labor.

An object of this invention is to provide a simple, efiicient and inexpensive method and means for stiffening fabric shoe uppers.

In accordance with this invention the toe portion of a fabric shoe upper cutout is impregnated with a thermoplastic composition to stifien without an extra thickness of material. The thermoplastic composition may be mounted on a transfer carrier sheet and applied to the fabric by heat and pressure from rollers through which they are fed. In an advantageous form of this invention, the thermoplastic composition is applied to its carrier sheet in a pattern slightly wider than the toe portion of the fabric cutout to facilitate registry during application.

Novel features and advantages of the present invention will become apparent to one skilled in the art from a reading of the following description in conjunction with the accompanying drawings wherein similar reference characters refer to similar parts and in which:

FIG. 1 is a perspective schematic diagram of the method performed in accordance with one embodiment of this invention;

FIG. 2 is a plan view of an untreated fabric shoe cutout shown in FIG. 1;

FIGS. 3 and 4 are cross-sectional views in elevation respectively taken through FIG. 1 along the lines 33 and 4-4;

FIG. 5 is a plan view of a stiffened blank made in accordance with the method shown in FIG. 1;

FIG. 6 is a cross-sectional view in elevation through FIG. 5 along the line 66; and

FIG. 7 is a perspective view of the blank shown in FIG. 5 in the arched form that is assumes in a finished shoe.

In FIG. 1 is shown a schematic view of the method of stiffening fabric shoe uppers. Thermoplastic stiffening substance 10 is first applied to carrier sheet 12 such as 18# MG paper in half-moon patterns similar to the toe portion of the shoe uppers. Substance 10 is printed on carrier paper 12 at for example 300 F. and varies in height from for example five to eight thousandths of an inch and is approximately two inches by five and a half inches. The transfer sheet 12, which includes the thermo- Patented Apr. 30, 15268 plastic patterns, is then fed through presure roller 16 and heat roller 18 at a speed of for example 20 feet per minute. As the transfer sheet is fed through the rollers, fabric shoe cutouts 14 are superimposed over the patterns, and the inner surface of each cutout contacts a corresponding pattern 10 between the rollers. Heating roller \18 operates at for example 560 F. to melt the thermoplastic substance. The thermoplastic substance is of a hot melt composition such as 300 parts polyeterpene resin as for example sold by Newport Industries under the name Nirez 1125, 300 parts Epolene C-10 (a trademark of the Eastman Chemical Products, Inc. for a low-molecularweight polyethylene), 600 parts Kalite (a trademark of the Diamond Alkali Co. for a calcium carbonate), and 5 parts Solvent Blue 36 dye which flows into the voids or interstices between the fibres of the fabric cutout. The dye is used to make patterns 10 visible to the operator but can be omitted. Although the composition of the thermoplastic substance varies in accordance with the desired stiffness, it is essential that the hot melt composition remain integral with the fabric and not transfer to the aluminum last during the subsequent curing of the shoe.

It is highly desirable that the stiffened shoe upper possess sufficient elasticity that when the toe portion is depressed, it can quickly bounce back to its original position. Accordingly, in an advantageous form of this invention stiffening substance 10 contains rubber as well as thermoplastic material. For example, the thermoplasti'c material, such as polyethylene, wax, or a terpene resin, is mixed with a low molecular weight rubber; and various curing agents are added to the rubber. When the shoe upper 20 is vulcanized, the rubber becomes cured and imparts the necessary resilience to the stiffened area. Thus the rubber comprises the main ingredient of substance 10, while the thermoplastic material provides an effective media to drive-in and penetrate the composition into the textile fibers of cut-outs 14.

A typical formation of substance 10 is as follows:

Methyl Zimate (a trademark of the R. T. Vanderbuilt Co. for an accelerator) 0.3 Methyl Tuad (a trademark of the R. T. Vanderbuilt Co. for an accelerator and vulcanizing agent) 1.2

Atomite filler (a trademark of the Thompson, Weinman & Co. for calcium carbonate) 20f Paraffin wax 3( As shown in FIG. 1, the thermoplastic stiffening sub stance is applied to carrier sheet 12 in a herringbone pattern so that the melted substance will not flow away frorr the cutout. As also shown in FIG. 1, pattern 10 is slightly wider than the toe portion of the fabric cutout so tha the same size pattern 10 can be used for all sizes of show uppers. Additionally the wider size facilitates an accuratt registry of the cutout and pattern. The stiffening substanc 10 is absorbed into the fabric shoe upper blank 20 and i: planar with its undersurface, as shown in FIG. 6, so a: not to irritate the foot. When pattern 10 is applied to th top surface of the fabric upper, it functions as a decoratioi or identification means, as well as stiffening and reinforc ing the fabric. As shown in FIG. 7, after blank 20 i. stiffened, it preserves an arched form when it is curvet into the shape that it assumes in a finished shoe.

This method of stiffening a shoe upper is particularl advantageous in that it permits the use of existing ma chinery, such as that used for transferring designs and identifications to textiles, to apply the stiffening patterns to the shoe upper cutouts.

What is claimed is:

1. A method of stiffening fabric uppers for shoes comprising the steps of applying a thermoplastic stiffening composition to a carrier sheet in a pattern corresponding to the toe portion of a shoe upper, feeding the carrier sheet through rollers, simultaneously feeding a fabric upper cutout through said rollers, contacting the toe portion of said fabric upper cutout with said thermoplastic pattern, and applying heat and pressure to said thermoplastic pattern and fabric upper cutout in said rollers whereby said thermoplastic composition enters the voids in said fabric upper cutout and becomes integral with it to stitfen it.

2. A method as set forth in claim 1 wherein said thermoplastic stiffening substance is made by mixing low molecular weight rubber with a thermoplastic material, and adding curing agents.

3. A method of stiffening fabric uppers for shoes com- References ited UNITED STATES PATENTS 2,133,346 10/1938 Diller et a1. 117163 2,187,005 1/1940 Almy 1l7163 2,277,941 3/ 1942 Alrny 1 17163 EARL M. BERGERT, Primary Examiner.

M. L. KATZ, Assistant Examiner. 

